1. Field of the Invention
This invention pertains to stoves and more particularly to stoves capable of incinerating volatiles.
2. Statement of the Prior Art
The increased demand for wood as a fuel has resulted in the now familiar problems of cost, conservation, and pollution, all of which are at least partially alleviated by increasing the efficiency of the combustion process and apparatus.
While it has long been recognized that the key to efficient burning of wood and similar solid fuels rich in volatiles is effective incineration of these volatiles, peaks in the rate at which these volatiles are released have been ignored, with the result that fuel is wasted and pollution increased because prior art apparatus are incapable of incinerating all of the volatiles released during these peak periods.
The resulting waste and pollution is particularly severe in home heating applications where combustion is a batch process in which a substantial quantity of fuel is allowed to burn before refueling.
Most of the prior art dates back to when solid fuels were the dominant fuels for home heating. Typical of early attempts at volatiles incineration is U.S. Pat. No. 268,682 issued to Jackson, in which a portion of the airborne combustion products are recycled through the combustion chamber. Such arrangements are ineffective because the airborne combustion products are too dilute to burn, and are instead carried up the flue by the through-air flow needed to sustain combustion.
Sherman, in U.S. Pat. No. 768,082, tried to improve matters by separating airborne combustion products into fractions to be recycled and fractions to be discharged into the flue, but his separation means is ineffective.
Jones and Shephard, in U.S. Pat. No. 921,612, disclose a stove having a coking chamber with an "airtight" top, the coking chamber being heated by and discharging into a surrounding combustion chamber. This arrangement is a definite improvement because the gases which are the primary pollutants exit the coking chamber at concentrations high enough to burn. A somewhat similar arrangement is disclosed by McMaster in U.S. Pat. No. 963,631. Unfortunately, both of these arrangements have limited coking capability because there is no throughflow in the coking chamber. Pollard introduces through-flow in U.S. Pat. No. 969,117.
More recent examples of recycling arrangements include Schwartzkopf, U.S. Pat. No. 2,172,715, Day, U.S. Pat. No. 2,556,840 and Van Raden, U.S. Pat. No. 3,754,869. However, like the prior art patents cited above, they do not take into account peaks in the production of volatiles.